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prop_number.c revision 1.26
      1 /*	$NetBSD: prop_number.c,v 1.26 2014/03/26 18:12:46 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <prop/prop_number.h>
     33 #include "prop_object_impl.h"
     34 #include "prop_rb_impl.h"
     35 
     36 #if defined(_KERNEL)
     37 #include <sys/systm.h>
     38 #elif defined(_STANDALONE)
     39 #include <sys/param.h>
     40 #include <lib/libkern/libkern.h>
     41 #else
     42 #include <errno.h>
     43 #include <stdlib.h>
     44 #endif
     45 
     46 struct _prop_number {
     47 	struct _prop_object	pn_obj;
     48 	struct rb_node		pn_link;
     49 	struct _prop_number_value {
     50 		union {
     51 			int64_t  pnu_signed;
     52 			uint64_t pnu_unsigned;
     53 		} pnv_un;
     54 #define	pnv_signed	pnv_un.pnu_signed
     55 #define	pnv_unsigned	pnv_un.pnu_unsigned
     56 		unsigned int	pnv_is_unsigned	:1,
     57 						:31;
     58 	} pn_value;
     59 };
     60 
     61 _PROP_POOL_INIT(_prop_number_pool, sizeof(struct _prop_number), "propnmbr")
     62 
     63 static _prop_object_free_rv_t
     64 		_prop_number_free(prop_stack_t, prop_object_t *);
     65 static bool	_prop_number_externalize(
     66 				struct _prop_object_externalize_context *,
     67 				void *);
     68 static _prop_object_equals_rv_t
     69 		_prop_number_equals(prop_object_t, prop_object_t,
     70 				    void **, void **,
     71 				    prop_object_t *, prop_object_t *);
     72 
     73 static void _prop_number_lock(void);
     74 static void _prop_number_unlock(void);
     75 
     76 static const struct _prop_object_type _prop_object_type_number = {
     77 	.pot_type	=	PROP_TYPE_NUMBER,
     78 	.pot_free	=	_prop_number_free,
     79 	.pot_extern	=	_prop_number_externalize,
     80 	.pot_equals	=	_prop_number_equals,
     81 	.pot_lock       =       _prop_number_lock,
     82 	.pot_unlock     =    	_prop_number_unlock,
     83 };
     84 
     85 #define	prop_object_is_number(x)	\
     86 	((x) != NULL && (x)->pn_obj.po_type == &_prop_object_type_number)
     87 
     88 /*
     89  * Number objects are immutable, and we are likely to have many number
     90  * objects that have the same value.  So, to save memory, we unique'ify
     91  * numbers so we only have one copy of each.
     92  */
     93 
     94 static int
     95 _prop_number_compare_values(const struct _prop_number_value *pnv1,
     96 			    const struct _prop_number_value *pnv2)
     97 {
     98 
     99 	/* Signed numbers are sorted before unsigned numbers. */
    100 
    101 	if (pnv1->pnv_is_unsigned) {
    102 		if (! pnv2->pnv_is_unsigned)
    103 			return (1);
    104 		if (pnv1->pnv_unsigned < pnv2->pnv_unsigned)
    105 			return (-1);
    106 		if (pnv1->pnv_unsigned > pnv2->pnv_unsigned)
    107 			return (1);
    108 		return (0);
    109 	}
    110 
    111 	if (pnv2->pnv_is_unsigned)
    112 		return (-1);
    113 	if (pnv1->pnv_signed < pnv2->pnv_signed)
    114 		return (-1);
    115 	if (pnv1->pnv_signed > pnv2->pnv_signed)
    116 		return (1);
    117 	return (0);
    118 }
    119 
    120 static int
    121 /*ARGSUSED*/
    122 _prop_number_rb_compare_nodes(void *ctx _PROP_ARG_UNUSED,
    123 			      const void *n1, const void *n2)
    124 {
    125 	const struct _prop_number *pn1 = n1;
    126 	const struct _prop_number *pn2 = n2;
    127 
    128 	return _prop_number_compare_values(&pn1->pn_value, &pn2->pn_value);
    129 }
    130 
    131 static int
    132 /*ARGSUSED*/
    133 _prop_number_rb_compare_key(void *ctx _PROP_ARG_UNUSED,
    134 			    const void *n, const void *v)
    135 {
    136 	const struct _prop_number *pn = n;
    137 	const struct _prop_number_value *pnv = v;
    138 
    139 	return _prop_number_compare_values(&pn->pn_value, pnv);
    140 }
    141 
    142 static const rb_tree_ops_t _prop_number_rb_tree_ops = {
    143 	.rbto_compare_nodes = _prop_number_rb_compare_nodes,
    144 	.rbto_compare_key = _prop_number_rb_compare_key,
    145 	.rbto_node_offset = offsetof(struct _prop_number, pn_link),
    146 	.rbto_context = NULL
    147 };
    148 
    149 static struct rb_tree _prop_number_tree;
    150 _PROP_MUTEX_DECL_STATIC(_prop_number_tree_mutex)
    151 
    152 /* ARGSUSED */
    153 static _prop_object_free_rv_t
    154 _prop_number_free(prop_stack_t stack, prop_object_t *obj)
    155 {
    156 	prop_number_t pn = *obj;
    157 
    158 	_prop_rb_tree_remove_node(&_prop_number_tree, pn);
    159 
    160 	_PROP_POOL_PUT(_prop_number_pool, pn);
    161 
    162 	return (_PROP_OBJECT_FREE_DONE);
    163 }
    164 
    165 _PROP_ONCE_DECL(_prop_number_init_once)
    166 
    167 static int
    168 _prop_number_init(void)
    169 {
    170 
    171 	_PROP_MUTEX_INIT(_prop_number_tree_mutex);
    172 	_prop_rb_tree_init(&_prop_number_tree, &_prop_number_rb_tree_ops);
    173 	return 0;
    174 }
    175 
    176 static void
    177 _prop_number_lock(void)
    178 {
    179 	/* XXX: init necessary? */
    180 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
    181 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
    182 }
    183 
    184 static void
    185 _prop_number_unlock(void)
    186 {
    187 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
    188 }
    189 
    190 static bool
    191 _prop_number_externalize(struct _prop_object_externalize_context *ctx,
    192 			 void *v)
    193 {
    194 	prop_number_t pn = v;
    195 	char tmpstr[32];
    196 
    197 	/*
    198 	 * For unsigned numbers, we output in hex.  For signed numbers,
    199 	 * we output in decimal.
    200 	 */
    201 	if (pn->pn_value.pnv_is_unsigned)
    202 		snprintf(tmpstr, sizeof(tmpstr), "0x%" PRIx64,
    203 		    pn->pn_value.pnv_unsigned);
    204 	else
    205 		snprintf(tmpstr, sizeof(tmpstr), "%" PRIi64,
    206 		    pn->pn_value.pnv_signed);
    207 
    208 	if (_prop_object_externalize_start_tag(ctx, "integer") == false ||
    209 	    _prop_object_externalize_append_cstring(ctx, tmpstr) == false ||
    210 	    _prop_object_externalize_end_tag(ctx, "integer") == false)
    211 		return (false);
    212 
    213 	return (true);
    214 }
    215 
    216 /* ARGSUSED */
    217 static _prop_object_equals_rv_t
    218 _prop_number_equals(prop_object_t v1, prop_object_t v2,
    219     void **stored_pointer1, void **stored_pointer2,
    220     prop_object_t *next_obj1, prop_object_t *next_obj2)
    221 {
    222 	prop_number_t num1 = v1;
    223 	prop_number_t num2 = v2;
    224 
    225 	/*
    226 	 * There is only ever one copy of a number object at any given
    227 	 * time, so we can reduce this to a simple pointer equality check
    228 	 * in the common case.
    229 	 */
    230 	if (num1 == num2)
    231 		return (_PROP_OBJECT_EQUALS_TRUE);
    232 
    233 	/*
    234 	 * If the numbers are the same signed-ness, then we know they
    235 	 * cannot be equal because they would have had pointer equality.
    236 	 */
    237 	if (num1->pn_value.pnv_is_unsigned == num2->pn_value.pnv_is_unsigned)
    238 		return (_PROP_OBJECT_EQUALS_FALSE);
    239 
    240 	/*
    241 	 * We now have one signed value and one unsigned value.  We can
    242 	 * compare them iff:
    243 	 *	- The unsigned value is not larger than the signed value
    244 	 *	  can represent.
    245 	 *	- The signed value is not smaller than the unsigned value
    246 	 *	  can represent.
    247 	 */
    248 	if (num1->pn_value.pnv_is_unsigned) {
    249 		/*
    250 		 * num1 is unsigned and num2 is signed.
    251 		 */
    252 		if (num1->pn_value.pnv_unsigned > INT64_MAX)
    253 			return (_PROP_OBJECT_EQUALS_FALSE);
    254 		if (num2->pn_value.pnv_signed < 0)
    255 			return (_PROP_OBJECT_EQUALS_FALSE);
    256 	} else {
    257 		/*
    258 		 * num1 is signed and num2 is unsigned.
    259 		 */
    260 		if (num1->pn_value.pnv_signed < 0)
    261 			return (_PROP_OBJECT_EQUALS_FALSE);
    262 		if (num2->pn_value.pnv_unsigned > INT64_MAX)
    263 			return (_PROP_OBJECT_EQUALS_FALSE);
    264 	}
    265 
    266 	if (num1->pn_value.pnv_signed == num2->pn_value.pnv_signed)
    267 		return _PROP_OBJECT_EQUALS_TRUE;
    268 	else
    269 		return _PROP_OBJECT_EQUALS_FALSE;
    270 }
    271 
    272 static prop_number_t
    273 _prop_number_alloc(const struct _prop_number_value *pnv)
    274 {
    275 	prop_number_t opn, pn, rpn;
    276 
    277 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
    278 
    279 	/*
    280 	 * Check to see if this already exists in the tree.  If it does,
    281 	 * we just retain it and return it.
    282 	 */
    283 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
    284 	opn = _prop_rb_tree_find(&_prop_number_tree, pnv);
    285 	if (opn != NULL) {
    286 		prop_object_retain(opn);
    287 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
    288 		return (opn);
    289 	}
    290 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
    291 
    292 	/*
    293 	 * Not in the tree.  Create it now.
    294 	 */
    295 
    296 	pn = _PROP_POOL_GET(_prop_number_pool);
    297 	if (pn == NULL)
    298 		return (NULL);
    299 
    300 	_prop_object_init(&pn->pn_obj, &_prop_object_type_number);
    301 
    302 	pn->pn_value = *pnv;
    303 
    304 	/*
    305 	 * We dropped the mutex when we allocated the new object, so
    306 	 * we have to check again if it is in the tree.
    307 	 */
    308 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
    309 	opn = _prop_rb_tree_find(&_prop_number_tree, pnv);
    310 	if (opn != NULL) {
    311 		prop_object_retain(opn);
    312 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
    313 		_PROP_POOL_PUT(_prop_number_pool, pn);
    314 		return (opn);
    315 	}
    316 	rpn = _prop_rb_tree_insert_node(&_prop_number_tree, pn);
    317 	_PROP_ASSERT(rpn == pn);
    318 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
    319 	return (rpn);
    320 }
    321 
    322 /*
    323  * prop_number_create_integer --
    324  *	Create a prop_number_t and initialize it with the
    325  *	provided integer value.
    326  */
    327 prop_number_t
    328 prop_number_create_integer(int64_t val)
    329 {
    330 	struct _prop_number_value pnv;
    331 
    332 	memset(&pnv, 0, sizeof(pnv));
    333 	pnv.pnv_signed = val;
    334 	pnv.pnv_is_unsigned = false;
    335 
    336 	return (_prop_number_alloc(&pnv));
    337 }
    338 
    339 /*
    340  * prop_number_create_unsigned_integer --
    341  *	Create a prop_number_t and initialize it with the
    342  *	provided unsigned integer value.
    343  */
    344 prop_number_t
    345 prop_number_create_unsigned_integer(uint64_t val)
    346 {
    347 	struct _prop_number_value pnv;
    348 
    349 	memset(&pnv, 0, sizeof(pnv));
    350 	pnv.pnv_unsigned = val;
    351 	pnv.pnv_is_unsigned = true;
    352 
    353 	return (_prop_number_alloc(&pnv));
    354 }
    355 
    356 /*
    357  * prop_number_copy --
    358  *	Copy a prop_number_t.
    359  */
    360 prop_number_t
    361 prop_number_copy(prop_number_t opn)
    362 {
    363 
    364 	if (! prop_object_is_number(opn))
    365 		return (NULL);
    366 
    367 	/*
    368 	 * Because we only ever allocate one object for any given
    369 	 * value, this can be reduced to a simple retain operation.
    370 	 */
    371 	prop_object_retain(opn);
    372 	return (opn);
    373 }
    374 
    375 /*
    376  * prop_number_unsigned --
    377  *	Returns true if the prop_number_t has an unsigned value.
    378  */
    379 bool
    380 prop_number_unsigned(prop_number_t pn)
    381 {
    382 
    383 	return (pn->pn_value.pnv_is_unsigned);
    384 }
    385 
    386 /*
    387  * prop_number_size --
    388  *	Return the size, in bits, required to hold the value of
    389  *	the specified number.
    390  */
    391 int
    392 prop_number_size(prop_number_t pn)
    393 {
    394 	struct _prop_number_value *pnv;
    395 
    396 	if (! prop_object_is_number(pn))
    397 		return (0);
    398 
    399 	pnv = &pn->pn_value;
    400 
    401 	if (pnv->pnv_is_unsigned) {
    402 		if (pnv->pnv_unsigned > UINT32_MAX)
    403 			return (64);
    404 		if (pnv->pnv_unsigned > UINT16_MAX)
    405 			return (32);
    406 		if (pnv->pnv_unsigned > UINT8_MAX)
    407 			return (16);
    408 		return (8);
    409 	}
    410 
    411 	if (pnv->pnv_signed > INT32_MAX || pnv->pnv_signed < INT32_MIN)
    412 	    	return (64);
    413 	if (pnv->pnv_signed > INT16_MAX || pnv->pnv_signed < INT16_MIN)
    414 		return (32);
    415 	if (pnv->pnv_signed > INT8_MAX  || pnv->pnv_signed < INT8_MIN)
    416 		return (16);
    417 	return (8);
    418 }
    419 
    420 /*
    421  * prop_number_integer_value --
    422  *	Get the integer value of a prop_number_t.
    423  */
    424 int64_t
    425 prop_number_integer_value(prop_number_t pn)
    426 {
    427 
    428 	/*
    429 	 * XXX Impossible to distinguish between "not a prop_number_t"
    430 	 * XXX and "prop_number_t has a value of 0".
    431 	 */
    432 	if (! prop_object_is_number(pn))
    433 		return (0);
    434 
    435 	return (pn->pn_value.pnv_signed);
    436 }
    437 
    438 /*
    439  * prop_number_unsigned_integer_value --
    440  *	Get the unsigned integer value of a prop_number_t.
    441  */
    442 uint64_t
    443 prop_number_unsigned_integer_value(prop_number_t pn)
    444 {
    445 
    446 	/*
    447 	 * XXX Impossible to distinguish between "not a prop_number_t"
    448 	 * XXX and "prop_number_t has a value of 0".
    449 	 */
    450 	if (! prop_object_is_number(pn))
    451 		return (0);
    452 
    453 	return (pn->pn_value.pnv_unsigned);
    454 }
    455 
    456 /*
    457  * prop_number_equals --
    458  *	Return true if two numbers are equivalent.
    459  */
    460 bool
    461 prop_number_equals(prop_number_t num1, prop_number_t num2)
    462 {
    463 	if (!prop_object_is_number(num1) || !prop_object_is_number(num2))
    464 		return (false);
    465 
    466 	return (prop_object_equals(num1, num2));
    467 }
    468 
    469 /*
    470  * prop_number_equals_integer --
    471  *	Return true if the number is equivalent to the specified integer.
    472  */
    473 bool
    474 prop_number_equals_integer(prop_number_t pn, int64_t val)
    475 {
    476 
    477 	if (! prop_object_is_number(pn))
    478 		return (false);
    479 
    480 	if (pn->pn_value.pnv_is_unsigned &&
    481 	    (pn->pn_value.pnv_unsigned > INT64_MAX || val < 0))
    482 		return (false);
    483 
    484 	return (pn->pn_value.pnv_signed == val);
    485 }
    486 
    487 /*
    488  * prop_number_equals_unsigned_integer --
    489  *	Return true if the number is equivalent to the specified
    490  *	unsigned integer.
    491  */
    492 bool
    493 prop_number_equals_unsigned_integer(prop_number_t pn, uint64_t val)
    494 {
    495 
    496 	if (! prop_object_is_number(pn))
    497 		return (false);
    498 
    499 	if (! pn->pn_value.pnv_is_unsigned &&
    500 	    (pn->pn_value.pnv_signed < 0 || val > INT64_MAX))
    501 		return (false);
    502 
    503 	return (pn->pn_value.pnv_unsigned == val);
    504 }
    505 
    506 static bool
    507 _prop_number_internalize_unsigned(struct _prop_object_internalize_context *ctx,
    508 				  struct _prop_number_value *pnv)
    509 {
    510 	char *cp;
    511 
    512 	_PROP_ASSERT(/*CONSTCOND*/sizeof(unsigned long long) ==
    513 		     sizeof(uint64_t));
    514 
    515 #ifndef _KERNEL
    516 	errno = 0;
    517 #endif
    518 	pnv->pnv_unsigned = (uint64_t) strtoull(ctx->poic_cp, &cp, 0);
    519 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
    520 	if (pnv->pnv_unsigned == UINT64_MAX && errno == ERANGE)
    521 		return (false);
    522 #endif
    523 	pnv->pnv_is_unsigned = true;
    524 	ctx->poic_cp = cp;
    525 
    526 	return (true);
    527 }
    528 
    529 static bool
    530 _prop_number_internalize_signed(struct _prop_object_internalize_context *ctx,
    531 				struct _prop_number_value *pnv)
    532 {
    533 	char *cp;
    534 
    535 	_PROP_ASSERT(/*CONSTCOND*/sizeof(long long) == sizeof(int64_t));
    536 
    537 #ifndef _KERNEL
    538 	errno = 0;
    539 #endif
    540 	pnv->pnv_signed = (int64_t) strtoll(ctx->poic_cp, &cp, 0);
    541 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
    542 	if ((pnv->pnv_signed == INT64_MAX || pnv->pnv_signed == INT64_MIN) &&
    543 	    errno == ERANGE)
    544 	    	return (false);
    545 #endif
    546 	pnv->pnv_is_unsigned = false;
    547 	ctx->poic_cp = cp;
    548 
    549 	return (true);
    550 }
    551 
    552 /*
    553  * _prop_number_internalize --
    554  *	Parse a <number>...</number> and return the object created from
    555  *	the external representation.
    556  */
    557 /* ARGSUSED */
    558 bool
    559 _prop_number_internalize(prop_stack_t stack, prop_object_t *obj,
    560     struct _prop_object_internalize_context *ctx)
    561 {
    562 	struct _prop_number_value pnv;
    563 
    564 	memset(&pnv, 0, sizeof(pnv));
    565 
    566 	/* No attributes, no empty elements. */
    567 	if (ctx->poic_tagattr != NULL || ctx->poic_is_empty_element)
    568 		return (true);
    569 
    570 	/*
    571 	 * If the first character is '-', then we treat as signed.
    572 	 * If the first two characters are "0x" (i.e. the number is
    573 	 * in hex), then we treat as unsigned.  Otherwise, we try
    574 	 * signed first, and if that fails (presumably due to ERANGE),
    575 	 * then we switch to unsigned.
    576 	 */
    577 	if (ctx->poic_cp[0] == '-') {
    578 		if (_prop_number_internalize_signed(ctx, &pnv) == false)
    579 			return (true);
    580 	} else if (ctx->poic_cp[0] == '0' && ctx->poic_cp[1] == 'x') {
    581 		if (_prop_number_internalize_unsigned(ctx, &pnv) == false)
    582 			return (true);
    583 	} else {
    584 		if (_prop_number_internalize_signed(ctx, &pnv) == false &&
    585 		    _prop_number_internalize_unsigned(ctx, &pnv) == false)
    586 		    	return (true);
    587 	}
    588 
    589 	if (_prop_object_internalize_find_tag(ctx, "integer",
    590 					      _PROP_TAG_TYPE_END) == false)
    591 		return (true);
    592 
    593 	*obj = _prop_number_alloc(&pnv);
    594 	return (true);
    595 }
    596